title: Association of national initiatives to improve cardiac arrest management with rates of bystander intervention and patient survival after out-of-hospital cardiac arrest.
abstract: OBJECTIVE
  Out-of-hospital cardiac arrest is a major health problem associated with poor outcomes. Early recognition and intervention are critical for patient survival. Bystander cardiopulmonary resuscitation (CPR) is one factor among many associated with improved survival.
  
  
  OBJECTIVE
  To examine temporal changes in bystander resuscitation attempts and survival during a 10-year period in which several national initiatives were taken to increase rates of bystander resuscitation and improve advanced care.
  
  
  METHODS
  Patients with out-of-hospital cardiac arrest for which resuscitation was attempted were identified between 2001 and 2010 in the nationwide Danish Cardiac Arrest Registry. Of 29,111 patients with cardiac arrest, we excluded those with presumed noncardiac cause of arrest (n = 7390) and those with cardiac arrests witnessed by emergency medical services personnel (n = 2253), leaving a study population of 19,468 patients.
  
  
  METHODS
  Temporal trends in bystander CPR, bystander defibrillation, 30-day survival, and 1-year survival.
  
  
  RESULTS
  The median age of patients was 72 years; 67.4% were men. Bystander CPR increased significantly during the study period, from 21.1% (95% CI, 18.8%-23.4%) in 2001 to 44.9% (95% CI, 42.6%-47.1%) in 2010 (P < .001), whereas use of defibrillation by bystanders remained low (1.1% [95% CI, 0.6%-1.9%] in 2001 to 2.2% [95% CI, 1.5%-2.9%] in 2010; P = .003). More patients achieved survival on hospital arrival (7.9% [95% CI, 6.4%-9.5%] in 2001 to 21.8% [95% CI, 19.8%-23.8%] in 2010; P < .001). Also, 30-day survival improved (3.5% [95% CI, 2.5%-4.5%] in 2001 to 10.8% [95% CI, 9.4%-12.2%] in 2010; P < .001), as did 1-year survival (2.9% [95% CI, 2.0%-3.9%] in 2001 to 10.2% [95% CI, 8.9%-11.6%] in 2010; P < .001). Despite a decrease in the incidence of out-of-hospital cardiac arrests during the study period (40.4 to 34.4 per 100,000 persons in 2001 and 2010, respectively; P = .002), the number of survivors per 100,000 persons increased significantly (P < .001). For the entire study period, bystander CPR was positively associated with 30-day survival, regardless of witnessed status (30-day survival for nonwitnessed cardiac arrest, 4.3% [95% CI, 3.4%-5.2%] with bystander CPR and 1.0% [95% CI, 0.8%-1.3%] without; odds ratio, 4.38 [95% CI, 3.17-6.06]). For witnessed arrest the corresponding values were 19.4% (95% CI, 18.1%-20.7%) vs 6.1% (95% CI, 5.4%-6.7%); odds ratio, 3.74 (95% CI, 3.26-4.28).
  
  
  CONCLUSIONS
  In Denmark between 2001 and 2010, an increase in survival following out-of-hospital cardiac arrest was significantly associated with a concomitant increase in bystander CPR. Because of the co-occurrence of other related initiatives, a causal relationship remains uncertain.
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Hellerup, Denmark. mads.wissenberg.joergensen@regionh.dk
authors.forename: Mads
authors.initials: M
authors.lastname: Wissenberg
authors.forename: Freddy K
authors.initials: FK
authors.lastname: Lippert
authors.forename: Fredrik
authors.initials: F
authors.lastname: Folke
authors.forename: Peter
authors.initials: P
authors.lastname: Weeke
authors.forename: Carolina Malta
authors.initials: CM
authors.lastname: Hansen
authors.forename: Erika Frischknecht
authors.initials: EF
authors.lastname: Christensen
authors.forename: Henning
authors.initials: H
authors.lastname: Jans
authors.forename: Poul Anders
authors.initials: PA
authors.lastname: Hansen
authors.forename: Torsten
authors.initials: T
authors.lastname: Lang-Jensen
authors.forename: Jonas Bjerring
authors.initials: JB
authors.lastname: Olesen
authors.forename: Jesper
authors.initials: J
authors.lastname: Lindhardsen
authors.forename: Emil L
authors.initials: EL
authors.lastname: Fosbol
authors.forename: Søren L
authors.initials: SL
authors.lastname: Nielsen
authors.forename: Gunnar H
authors.initials: GH
authors.lastname: Gislason
authors.forename: Lars
authors.initials: L
authors.lastname: Kober
authors.forename: Christian
authors.initials: C
authors.lastname: Torp-Pedersen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation; D015984:Causality; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006078:Government Programs; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality* / Q000628:therapy*; D012042:Registries / Q000706:statistics & numerical data; D016019:Survival Analysis; D013997:Time Factors